Electronic control type throttle valve apparatus, non-contact type rotation angle detecting apparatus used in electonic control type throttle valve apparatus etc. and signal processing apparatus for hall element

ABSTRACT

In an electronic control type throttle valve apparatus, a throttle valve position sensor includes a magnet provided at a throttle valve shaft and a hall element which output changes in accordance with the rotational deviation of the magnet. The hall element is housed within a sensor chip together with an amplifier circuit. In a control unit provided separately from the sensor chip, there are provided with an A/D conversion circuit for converting an analog output from the hall element through the amplifier circuit into a digital signal and a digital processing circuit for performing temperature compensation and zero-span adjustment of the hall element in a digital manner.

BACKGROUND OF THE INVENTION

The present invention relates to a rotation angle detecting apparatususing a hall element, a signal processing apparatus for the hall elementand a throttle valve apparatus for an automobile using the rotationangle detecting apparatus, and preferably relates to an electroniccontrol type throttle valve apparatus provided with a throttle valvedriven by a motor.

Conventionally, a non-contact type rotation angle detecting apparatus(that is, a rotation angle sensor) has been known in which magnets areattached to a rotation shaft and the rotation angle of the rotationshaft is detected in cooperation with the magnets and hall elementsdisposed at the periphery of the rotation shaft.

In such a kind of the rotation angle detecting apparatus, it is known toconstitute the hall elements and a circuit (a zero span adjustmentcircuit) for performing zero-span adjustment of the outputs of the hallelements and/or a circuit (a temperature compensation circuit) forcompensating temperature drift of the hall elements as a singlesemiconductor package (chip) thereby to enhance the function of thesensor. Such a configuration is generally known as a hall IC.

For example, JP-A-8-68606 discloses the technique in which as a sensingunit for detecting a rotation angle, an EPROM and a registerconstituting an amplifier circuit and an adjustment circuit etc. areintegrated together with a magnetic sensitive element formed by hallelements thereby to constitute a single chip.

Further, JP-A-2000-74613 discloses the technique that in a throttlevalve sensor, a hall element generates a hall voltage in response tomagnetic flux density changed in accordance with the opening degree ofthe throttle valve and an IC receives the hall voltage thereby toperform various kinds of processing such as temperature characteristiccompensation.

SUMMARY OF THE INVENTION

In the aforesaid throttle valve apparatus, in order to perform the zerospan adjustment or the temperature compensation with high accuracy, itis required to convert the output of the hall element into a digitalsignal from an analog signal to process the signal in a digital manner

To this end, in the conventional rotation angle detecting apparatus ofthe semiconductor package type (hall IC), the hall elements, the A/D(analog to digital) conversion circuit, the zero span adjustment circuitand the temperature compensation circuit are collectively housed withina single mold resin. Further, in the case of transmitting the output ofthe hall IC to a control unit disposed outside, an analog transmissionsystem is employed since a microcomputer on a signal receiving side isconfigured to convert the along input into a digital signal. Thus, a D/A(digital to analog) conversion circuit for converting the digital signalinto an analog signal is also housed within the mold resin for the hallIC.

When both the A/D conversion circuit and the D/A conversion circuit areprovided within the hall IC, it takes 4 milli-seconds (ms) as a signalprocessing time in total until the signal having been inputted into thehall IC is outputted therefrom, that is, 2 ms for each of the A/Dconversion and the D/A conversion.

Due to the aforesaid processing time, there arises the following problemin the control of an internal combustion engine for an automobile, forexample. That is, when the hall IC configured in the aforesaid manner isemployed as a sensor for detecting the opening degree (rotation angle)of a throttle valve for controlling an air flow rate, there arises atime lag until the output change of the hall element itself respondingto the change of the opening degree appears at the output terminal ofthe sensor, that is, at the output terminal of the hall IC as the outputchange of the hall IC. Thus, since neither of the real-time detection ofthe opening degree or the real-time control of the opening degree can beperformed, there arises signal delay in the response.

Such a problem is remarkable in the case where an analog signal isconverted into a digital signal and then taken in like a microcomputer(for example, an engine control unit). When considering the A/Dconversion processing for inputting data at the microcomputer, 2 ms isfurther delayed in the signal response.

Further considering from another point of view, in the case ofconverting an analog signal into a digital signal and taking-in thedigital signal like a microcomputer, it is not reasonable to performboth the A/D and D/A conversions before the taking-in operation at themicrocomputer since the A/D conversion is duplicated at the hall IC andthe microcomputer.

Accordingly, an object of the present invention is to eliminate wastefulor duplicated conversion processing of a hall element so that the outputof the hall element can be applied to a processing circuit at thesucceeding stage as early as possible thereby not to cause control delayetc. of a device, for example.

Another object of the present invention is to provide suitableconfiguration for the rotation angle detecting apparatus, using such ahall element, of a throttle valve shaft for an automobile.

Still another object of the present invention is to provide a throttlevalve apparatus attached with such a sensor.

In order to attain the aforesaid object, the present invention isbasically configured in the following manner.

(1) A non-contact type rotation angle detection apparatus in which ahall element generates an electric signal relating to a rotation angleof a rotation shaft in accordance with mutual operation between a magnetattached to the rotation shaft and the hall element, the apparatusfurther including:

-   -   a circuit mold chip in which both the hall element and an        amplifier for amplifying an output of the hall element are        sealed in a mold resin;    -   an analog-to-digital conversion circuit for converting an analog        output of the amplifier outputted from an output terminal of the        circuit mold chip into a digital signal at an outside of the        circuit mold chip;    -   an electric conductor for coupling between the circuit mold chip        and the analog-to-digital conversion circuit; and    -   a compensation circuit for subjecting an output of the        analog-to-digital conversion circuit to zero-span adjustment and        temperature compensation in a digital manner.

The following configuration is proposed as a related invention forattaining the same object.

(2) A signal processing apparatus for a hall element includes:

-   -   a hall element;    -   a microcomputer for inputting an output of the hall element        having been converted from an analog signal into a digital        signal and outputting an electric signal relating to the output        of the hall element; and    -   a signal transmission path from an output terminal of the hall        element to an input interface of the microcomputer, wherein    -   the signal transmission path has only one analog-to-digital        conversion circuit.

Preferably, the output of the analog-to-digital conversion circuit istransferred to the microcomputer through a communication line.

(3) An output signal processing apparatus for a hall element whichincludes two hall elements disposed at different positions along arotation direction of a rotation shaft and each responsive to rotationof the rotation shaft, and which is arranged to output a signal relatingto a rotation position of the rotation shaft based on output signalsfrom the two hall elements, the output signal processing apparatus for ahall element including:

-   -   a casing for holding the two hall elements;    -   two amplifiers for amplifying outputs of the two hall elements,        the two amplifiers being attached to the casing;    -   a connector, formed at the casing, for extracting outputs of the        two amplifiers;    -   a circuit apparatus, coupled to the connector, for receiving the        output signal of the hall element, wherein an analog-to-digital        conversion circuit for converting the output signal of the hall        element is provided at the circuit apparatus.

(4) An electronic control type throttle valve apparatus includes:

-   -   a microcomputer for subjecting a signal necessary for        controlling a throttle valve to a digital calculation in        accordance with an operation state of an engine;    -   a motor driven by an electric signal obtained through the        digital calculation;    -   the throttle valve which opening degree is controlled in        accordance with the motor; and    -   a throttle valve position sensor for detecting a rotation angle        of the throttle valve in accordance with an output of a hall        element, wherein    -   a time period required for input processing of the output of the        hall element is shorter than a calculation period required for        digital calculation of the electric signal for controlling the        motor.

(5) In an electronic control type throttle valve apparatus whichincludes a magnet attached to a throttle valve shat and rotatestherewith and a hall element responsive to magnetic field of the magnet,and which is arranged in a manner that the hall element generates anelectric signal relating to a rotation angle of the throttle valveshaft, the electronic control type throttle valve apparatus including:

-   -   a connector having a signal extracting terminal for extracting        an output signal of the hall element; and    -   a signal transmission path from an output terminal of the hall        element to a terminal of the connector which is arranged in a        manner that a time period required for the signal generated at        the hall element to appear at the signal extracting terminal is        shorter than a time required for analog-to-digital conversion.

Preferably, the signal transmission path includes an amplifier foramplifying the output of the hall element and an electric conductor forcoupling between the amplifier and the terminal of the connector.

(6) An electronic control type throttle valve apparatus includes:

-   -   a microcomputer for subjecting a signal necessary for        controlling a throttle valve to a digital calculation in        accordance with an operation state of an engine;    -   a motor driven by an electric signal obtained through the        digital calculation;    -   the throttle valve which opening degree is controlled in        accordance with the motor;    -   a throttle valve position sensor for detecting a rotation angle        of the throttle valve in accordance with an output of a hall        element, the throttle valve position sensor including a magnet        which deviates in response to rotation of the throttle valve        shaft and two hall elements disposed at different positions in        rotation direction of the throttle valve shaft and the throttle        valve position sensor being arranged to output a signal relating        to a rotation position of the throttle valve shaft;    -   two circuit mold chips each having corresponding one of the hall        elements and an amplifier for amplifying an output of the        corresponding one of the hall elements, and each sealed within        mold resin;    -   a casing for holding the circuit mold chips;    -   a connector, formed at the casing, for taking out outputs of the        two amplifiers; and    -   an electric conductor formed at the casing through molding so as        to couple between output terminals of the circuit mold chips and        the connector.

Preferably, a deceleration gear mechanism is provided between an outputshaft of the motor and the throttle valve shaft, wherein the casing alsoserves as a gear cover for covering the deceleration gear mechanism.

(7) An electronic control type throttle valve apparatus, includes:

-   -   an electrically driven actuator for driving a throttle valve        provided at an intake air path of an internal combustion engine        in accordance with a control signal;    -   a throttle valve position sensor for detecting an opening degree        of the throttle valve; and    -   a control unit provided separately from a sensor chip, wherein    -   the throttle valve position sensor includes a magnet provided at        a throttle valve shaft and a hall element which output changes        in accordance with rotational deviation of the magnet, the hall        element is housed within the sensor chip together with an        amplifier circuit, and the control unit is provided with an        analog-to-digital conversion circuit and a circuit for        performing temperature compensation and zero-span adjustment of        the hall element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit block diagram showing the configuration of anelectron control type throttle valve apparatus according to the firstembodiment of the present invention.

FIG. 2 is a schematic diagram showing a relation between a gear coverand sensor chips (circuit mold chips) in the first embodiment.

FIG. 3 is a circuit block diagram showing the configuration of anelectron control type throttle valve apparatus according to the secondembodiment of the present invention.

FIG. 4 is a circuit block diagram showing the configuration of anelectron control type throttle valve apparatus according to the thirdembodiment of the present invention.

FIG. 5 is a circuit block diagram showing the configuration of anelectron control type throttle valve apparatus according to the fourthembodiment of the present invention.

FIG. 6 is a circuit diagram showing the configuration of a sensor chipin the fourth embodiment.

FIG. 7 is a perspective view showing the principle of a magneticsensitive type rotation position sensor.

FIG. 8 is an oblique perspective view of FIG. 7.

FIG. 9 is an oblique perspective view in which magnetizing direction isadded in FIG. 8.

FIG. 10 is an oblique perspective view in which vectors of magneticdensity are added in FIG. 8.

FIG. 11 is a longitudinal sectional diagram (a sectional diagram along aline A-A in FIG. 14) showing a state where the rotation position sensor(throttle position sensor) according to the first embodiment is mountedin a throttle body.

FIG. 12 is a sectional diagram showing only the rotation position sensorin the configuration of FIG. 11.

FIG. 13 is a top view in which a cover and an upper stator are removedfrom the rotation position sensor shown in FIG. 14 thereby to show theinner structure of a housing and also is a top view showing a connectorportion.

FIG. 14 is a plan view of the gear cover.

FIG. 15 is a partial enlarged perspective view of FIG. 13.

FIG. 16 is a partial enlarged view of FIG. 13.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention will be explained with referenceto the accompanying drawings.

FIG. 1 is a circuit block diagram showing the configuration of anelectron control type throttle valve apparatus according to theembodiment of the present invention.

The throttle valve apparatus according to the embodiment is providedwith, when classified briefly, (1) a throttle valve mechanism Aconfigured by a throttle valve 310 housed within a throttle body 300 anda deceleration mechanism 303 etc. for transmitting power of a motor 300(electrically driven actuator) to a throttle valve shaft 40, (2) asensor module B for detecting the rotation angle (opening degree) of thethrottle valve 310, and (3) a throttle control module (hereinafterreferred to a TCM) for calculating a throttle valve control signal basedon an output signal from the sensor module B.

The throttle body 300 constitutes a part of an intake air path of aninternal combustion engine and the throttle valve 310 is disposed at theintake air path.

The sensor module B acts as a throttle position sensor for detecting theopening degree of the throttle valve and is configured by a permanentmagnet 31 provided at an end 41 of the throttle valve shaft 40 and chips6 which output change in accordance with the rotation deviation of thepermanent magnet 31. Each of the chips 6 is formed as a single chip soas to include a hall element (a magnetic sensitive element) and anamplifier circuit for amplifying the output of the hall element. Thesensor chip may be called as a hall IC. Although each of the sensorchips acts sufficiently, two sensor chips are employed so as to performthe backup operation to each other when one of these sensor chipsbecomes failure or to perform the check operation at the time of failurediagnosis.

The principle of the sensing operation by the sensor chip 6 using thehall sensor will be explained with reference to FIGS. 6 to 10.

FIG. 8 is a diagram seen through an upper stator 4 and showing thearrangement of the upper stator 4, a lower stator 2 (2A, 2B), a rotor(permanent magnet) 31 and the chips 6.

As shown in FIG. 8, the ring-shaped permanent magnet 31 is attached tothe tip end of the rotation shaft (the throttle valve shaft) 41 servingas a detected member to constitute the rotor. As shown in FIGS. 7 and 8,the rotor 31 is disposed between magnetic plates (the upper stator andthe lower stator) 4, 2 (2A, 2B) disposed in the vertical direction so asto oppose to each other. At least one of the upper and lower stators isarranged in a split manner in the horizontal direction. In thisembodiment, the lower stator 2 is divided into two pieces 2A and 2Bthereby to secure an air gap G therebetween.

The upper stator 4 and the lower stators 2A, 2B have magneticprojections 401, 402 and 201, 202 serving as magnetic flux convergingportions, respectively. The magnetic projections 401 and 201 aredisposed so as to oppose to each other with a uniform gap therebetween.The magnetic projections 402 and 202 are disposed so as to oppose toeach other in the similar manner. The chips 6 having the hall elements(magnetic sensitive elements) are sandwiched between the magneticprojections 401, 201 and the magnetic projections 402, 202,respectively.

Although the magnetic projection at the upper stator and the magneticprojection at the lower stator are integrally formed in this embodiment,the magnetic projection at the upper stator may be formed separatelyfrom the magnetic projection at the lower stator in advance and thesemagnetic projections may be combined by the welding process etc. Themagnetic projections are disposed at positions opposing to the outerperiphery of the rotor 31 through the air gap.

The sensor chip 6 is configured by a circuit mold chip which is formedin a manner that the hall element and the amplifier circuit areintegrated and sealed in a mold resin thereby to form in a chip shape.

The rotor 31 is magnetized almost in vertical direction as shown byarrows in FIG. 9. That is, the rotor 31 is magnetized upward in therange of 180 degrees in the rotational direction and magnetized downwardin the range of the remaining 180 degrees.

The magnetic density fluxes in this case are distributed as shown byarrows in FIG. 10. That is, the magnetic field generated by the rotor 31forms a magnetic path passing through the upper and lower stators 401,402. The magnetic fluxes converged by the magnetic projections 401, 201and the magnetic projections 402, 202 pass through the correspondingchips 6, respectively. An amount of the magnetic fluxes passing throughthe sensor chip changes in accordance with the rotational position ofthe rotor 31. A signal according to the change of the amount of themagnetic fluxes is outputted from the sensor chip 6, whereby it ispossible to detect the rotational position (rotation angle).

The circuit configuration of the rotation angle detection apparatus willbe explained with reference to FIG. 6.

FIG. 6 shows an example of the circuit configuration of the rotationangle detection apparatus in the case of using the two sensor chips (thecircuit module chips) 6. Each of the chips 6 is coupled between a powersource VDD and the ground GND. The output of one of the hall ICs 6 is 2is taken from an output terminal S1 and the output of the other of thehall ICs 6 is 2 is taken from an output terminal S2.

In this embodiment, a capacitor C3 is coupled between the power sourceVDD and the ground GND, a capacitor C1 is coupled between the outputterminal S1 and the ground GND and a capacitor C2 is coupled between theoutput terminal S2 and the ground GND.

The capacitor C3 is used for protecting from electric disturbance noiseand surge. Each of the capacitors C1 and C2 operates as an element notonly for protecting from electric disturbance noise and surge but alsofor filtering the internal noise of the hall IC. Each of the capacitorsC1, C2 and C3 may be used by itself or may be used together with a zenerdiode and a resistor (each not shown), as the occasion demands.

The explanation will be made as to the TCM shown in FIG. 1.

The TCM includes input/output interfaces 50, 51 corresponding to thechips 6, respectively; storage devices 52, 53 for storing zero-span data(zero-point data) and a temperature characteristic table relating to theoutputs from the chips 6, respectively; digital processing circuits(temperature compensation circuits and zero-span adjusting circuits) 54,55 for subjecting the outputs of the chips 6 to zero-span (zero-point)adjustment and temperature compensation by digital processings,respectively; a microcomputer 56 for controlling the opening degree ofthe throttle valve; and a driving circuit 57 for driving a throttlevalve driving motor.

The outputs from the chips 6 are converted into digital data by theinput/output interfaces 50, 51 and sent to the circuits r54, 55,respectively. The zero-span data is obtained in a manner that theoutputs of the chips 6 obtained when the throttle valve opening degreeis set to zero (the minimum) are subjected to the digital processing andthe values obtained by the digital processing are stored in the storagedevices 52, 53 as zero-point outputs, respectively.

Each of the storage devices 52, 53 has a plurality of the temperaturecharacteristics tables relating to the output of the hall element incorrespondence with temperature ranges. Each of the digital processingcircuits 54, 55 subjects the outputs (the throttle valve opening degreesignal and the rotation angle signal) of the corresponding sensor chip 6having been A/D converted to the zero-point adjustment and also to thetemperature compensation (temperature correction) by using thetemperature characteristic tables according to the ambient temperatureof the sensor chip 6 and sends data thus subjected to the zero-pointadjustment and the temperature compensation to the microcomputer 56.

The microcomputer 56 serves as a main portion for controlling thethrottle valve opening degree and includes a ROM for storing controlprogram, a RAM for storing the throttle valve opening degree signal etc.in a randomly rewritable state, and a central processing unit (CPU)which inputs a target throttle valve opening degree inputted from anengine control unit (ECU) disposed outside and an actual throttle valveopening degree signal thereby to calculate a control signal so that thethrottle valve has the target opening degree. The driving circuit 57 isdriven by the control signal from the CPU thereby to control the motorcurrent. The driving circuit 57 is formed by a pulse width modulationcircuit (PWM), for example.

The sensor chips (the circuit mold chips) 6 are incorporated togetherwith the stators 4, 2 (2A, 2B) within a gear cover 100 made of resin tobe attached to the throttle body 300 (the detailed example of themounting structure thereof will be explained later with reference toFIG. 11). FIG. 2 is a schematic diagram showing a state where thestators are omitted and the two chips 6 are incorporated within thecover 100. In the figure, the chips 6 are illustrated exaggeratedly intheir sizes, and in fact the ratio of the chips 6 occupying within thegear cover 100 is small as shown in FIG. 13, for example.

Each of the chips 6 is formed by sealing both a magnetic sensitiveelement (hall element) 61 and an amplifier circuit (AMP) 62 togetherwithin a mold resin (shown by an alternate long and short dash line) andis provided with, as terminals, a power source terminal (Vcc) 8A, aground terminal (GND) 8B and output terminals (S1, S2) 8C.

A connector case 60 is integrally formed with the resin cover 100. Apower source line 7A, a ground line 7B, output signal lines 7C1, 7C2 areburied within the resin cover 100 through the insert molding. The oneends 7A 7B of these lines and the output signal lines 7C1 7C2 areexposed at the inner surface of the cover 100 and coupled to thecorresponding terminals 8A, 8B, 8C of the chips 6. The other ends 70A,70B, 70C1, 70C2 thereof protrude within the connector case 60 asconnector terminals.

The power source lines (+line) 7D and (−line) 7E of the motor 302 fordriving the throttle valve are buried within the resin cover 100 throughthe insert molding. The one ends 7D 7E of these power source lines areexposed at the inner surface of the cover 100 and coupled to the powersource terminals of the motor 302, and the other ends 70D, 70E thereofprotrude within the connector case 60 as connector terminals.

According to the embodiment shown in FIGS. 1 and 2, the output signalsof the hall element 61 are subjected to the A/D conversion at theoutside of the circuit mold chip 6. As a signal processing apparatus forthe hall element, only an A/D converter 50 (51) is provided at a signaltransmission path from the output terminal of the hall element 61 to theinput interface of the microcomputer 54. According to such aconfiguration, it is not necessary to perform the A/D conversion, theD/A conversion and the A/D conversion in the path from the sensor chip(hall IC) 6 to the microcomputer 54 like the conventional technique butit is required to perform only the A/D conversion in the path. Thus, itis possible to realize the rotation angle detecting apparatus (thethrottle position sensor) which is high in the signal transmission speedand excellent in the responsibility. That is, a time period required forthe input processing of the output signal of the hall element 61 can bemade shorter than a calculation period required for the digitalcalculation of the electric signal for controlling the motor. Further,the signal transmission path from the output terminal of the hallelement to the connecter terminal can be configured so that a timeperiod required for the signal generated from the hall element 61 toappear at the signal extracting terminals 70C1, 70C2 is made shorterthan a time period required for the A/D conversion.

FIG. 11 is a longitudinal sectional diagram (a sectional diagram along aline A-A in FIG. 14) of a non-contact type throttle valve apparatusaccording to the embodiment of the present invention. FIG. 12 is asectional diagram showing only the rotation angle detection apparatus(the throttle position sensor) in the configuration of FIG. 11. FIG. 13is a top view in which the sensor cover 5 and the upper stator 4 areremoved from the gear cover 100 thereby to show the inner side of thehousing and also is a top view showing the connector portion. FIG. 14 isa plan view of the gear cover 100 to be attached to the throttle body300. FIG. 15 is a partial perspective view of FIG. 13, and FIG. 16 is apartially enlarged view of FIG. 13.

In this embodiment, the gear cover 100 for the gear mechanism 303 fortransmitting the motor power is attached to the throttle body 300 havingthe throttle valve 310. The throttle position sensor (the throttle valverotation angle detection apparatus) is attached to the gear cover 100.

As shown in FIGS. 13 and 14, the gear cover 100 is made of compositeresin and is formed integrally with a connector 60 having externalconnection terminals 70A, 70B, 70C1, 70C2, 70D, 70E for electricallycoupling with an external device and the power source.

The throttle body 300 is integrally formed with a motor housing 301 forhousing the motor 302 for driving the throttle valve shaft 40 and a gearhousing 306 for disposing the gear mechanism 303 and a defaultmechanism. The gear cover 100 covers the gear housing 306 and a sensorhousing 1 is formed at the gear cover 100.

The power source terminal 302A and the ground terminal 302B of the motor302 are coupled to intermediate terminals 312A, 312B provided at thegear cover 100 through a coupling metal member 311, respectively.

The power of the motor 302 is transmitted to the throttle valve shaft 40through the gear mechanism 303 (a pinion 303A, an intermediate gear303B, a final gear 303C) thereby to drive the throttle valve 310.

As shown in FIG. 12, the housing 1 is provided at the bottom wallthereof with a lateral hole 45 for introducing the one end 41 of therotation shaft 40. At the inner bottom of the housing 1, two recessportions 3 for housing the lower stators 2A, 2B therein are formedseparately in the left and right direction at the periphery of thelateral hole 45. The lower stators 2A, 2B are attached to the recessportions 3 by means of adhesive, respectively. Although the lowerstators 2A, 2B are held by the housing 1 by means of the adhesive, thelower stators 2A, 2B may be held by the housing 1 through the insertmolding in stead of the adhesive.

In the housing 1, a spacer 12 (see FIG. 15) having both function ofrelatively positioning the upper stator 4 with the lower stators 2A, 2Band maintaining the space between both the upper an lower stators isformed integrally with the housing 1.

The spacer 12 is formed so as to cover the four corners of the lowerstators 2A, 2B and L-shaped convex portions 12A for receiving the cornerportions of the upper stator 4 are formed at the upper surface of thespacer.

As shown in FIG. 14, the connector 60 is integrally formed with thecover 100 at the side surface of the gear cover 100. The externalconnection terminals formed at the connector 60 through the insertmolding include the terminals 70A, 70B, 70C1, 70C2 used for the two hallICs 6 of the rotational position sensor and the terminals 70D, 70E forthe motor for driving the throttle valve, as shown in FIG. 13. In thisembodiment, as to the power source terminal VDD (the external connectionterminal 70A) and the GND terminal (the external connection terminal70B) for the two chips 6, these terminals VDD and GND are shared by thetwo chips 6. In the plan view of FIG. 13, the external connectionterminal 70B is hidden by the terminal 70C2 and so not shown, also theexternal connection terminal 70C1 is hidden by the terminal 70A and sonot shown, and further the external connection terminal 70E is hidden bythe terminal 70D and so not shown.

As shown in FIG. 13, the external connection terminals relating to therotational position sensor have four terminals in total, that is, theone power source terminal 70A (VDD), the one ground terminal 70B (GND)and the two sensor input/output terminals 70C1, 70C2 (S1, S2). Theexternal connection terminals have six terminals in total, that is,these four terminals relating to the sensor, the one power sourceterminal 70D for the motor and the ground terminal 70E therefore. Theseterminals are disposed in two lines each having the two terminals.

The terminal 7A corresponding to the power source terminal VDD (theexternal connection terminal 70A), the terminal 7B corresponding to theground terminal (the external connection terminal 70B), the terminals7C1, 7C2 corresponding to the sensor output terminals S1, S2 (theexternal connection terminals 70C1, 70C2), and the terminals 7D, 7Ecorresponding to the motor terminals 70D, 70E are buried in the gearcover 100 through the insert molding.

Of the conductors 7A, 7B, 7C1, 7C2, the power source conductor 7A isdivided into two pieces on the way thereof and the one end 7A of each ofthe divided pieces is drawn to the combined portion with the powersource terminal 8A of the corresponding hall IC 6. The ground conductor7B is also divided into two pieces on the way thereof and the one end 7Bof each of the divided pieces is drawn to the combined portion with theground terminal 8A of the corresponding hall IC 6.

The conductors 7A, 7B, 7C1, 7C2 are exposed at the parts 7A 7B 7C1 7C2thereof so as to be coupled to the circuit elements such as a capacitor20, respectively. Of these parts, the one exposed portion 7A is providedin correspondence with the power source conductor 7A, the two exposedportions 7B are provided in correspondence with the ground conductors7B, the one exposed portion 7C1 and the one exposed portion 7C2 areprovided in correspondence with the sensor output conductors 7C1, 7C2,respectively (see FIGS. 13 and 14).

These exposed conductor portions are arranged in the order of the sensoroutput conductor exposed portion 7C1 the ground conductor exposedportion 7B the power source conductor exposed portion 7A the groundconductor exposed portion 7B and the sensor output conductor exposedportion 7C2.

The circuit element such as the capacitor 20 is coupled between thesensor output conductor exposed portion 7C1 nd the ground conductorexposed portion 7B between the power source conductor exposed portion 7Aand the ground conductor exposed portion 7B and also between the groundconductor exposed portion 7B and the sensor output conductor exposedportion 7C2 This circuit element is inserted into a recess portion 15provided between the conductor exposed portions at the inner surface ofthe gear cover 100.

As shown in FIG. 15, the one ends 7A 7B 7C1 7C2 of the conductors 7A,7B, 7C1, 7C2 are exposed on the inner wall surface of the housing atpredetermined positions of the input/output terminals 8A, 8B, 8C of thehall IC 6. The one ends 7A 7B 7C1 7C2 of the conductors are bent so asto protrude on the inner wall surface of the housing.

As shown in FIG. 16, at the inner wall in the periphery of the portionswhere the lower stators 2A, 2B of the housing 1 are provided,groove-shaped guides 10 are provided so as to conduct the input/outputterminals 8A, 8B, 8C of the hall IC 6 to the terminal combining portionswith the conductor one ends 7A 7B 7C1 7C2 The input/output terminals 8A,8B, 8C are fit into the guides 10 and so guided thereby. The guides 10also serve to position the sensor chip 6.

The input/output terminals 8A, 8B, 8C of the sensor chip 6 are combinedwith the conductor one ends 7A 7B 7C1 7C2 through the welding operation.The terminals 8A, 8B, 8C are bent so as to be combined at their endportions with the conductor one ends 7A 7B 7C1 7C2.

As shown in FIGS. 11 and 12, a magnet holder 30 is attached to the oneend 41 of the rotation shaft 40. The magnet holder 30 holds the annularpermanent magnet (rotor) 31. A reference numeral 32 depicts a shaft holeprovided at the holder 30 (see FIG. 13). The rotation shaft 40 isapplied with a return force by a return spring 305. A reference numeral44 depicts a C ring.

As shown in FIG. 12, the upper stator 4 is adhered to a projection 5provided at the inner side of the sensor cover 5 of the sensor housing 1and so held by the sensor cover 5. The sensor cover 5 is adhered to theupper opening of the housing 1 in a manner that the four corner portionsof the upper stator 4 are positioned and held at the upper surface ofthe spacer 12. The upper stator 4 is positioned with respect to thelower stators 2A, 2B by the spacer 12. The spacer 12 holds a uniform gapbetween the upper stator and the lower stator. The chips 6 arepositioned between the magnetic projections 401 and 201 and also betweenthe magnetic projections 402 and 202, respectively.

Since the wire harness within the housing 1 of the non-contact typerotational position sensor is almost formed through the insert molding,the space within the housing is prevented from being complicated by thewiring and so it makes possible to perform the assembling procedure ofparts and the electric coupling procedure of the circuit elements.

The sensor chip 6, which is required to have sufficient positioningaccuracy, can be positioned simply and further the positioning betweenthe terminals 8A to 8C and the conductors 7A to 7C can also bepositioned easily, by merely fitting the terminals 8A to 8C thereof intothe guide grooves 10.

Both the relative positioning between the upper stator 4 and the lowerstators 2A, 2B and the holding of the uniform gap therebetween can beperformed simply with a high accuracy by the spacer 12 with an L-shapedprojection 12A provided at the housing 1.

The connector 60 is formed at the one side of the gear cover 100 and theexternal connection terminals 70A to 70E are formed within the connectorthrough the insert molding.

The sensor chip can be protected from the electric external noise andserge with the relatively simple configuration. Further, since thecapacitor and the zener diode etc. as the circuit elements forprotecting from the electric external noise and serge are not requiredto be housed within a highly integrated IC, the sensor chip can beprevented from being larger in size. The circuit elements such as thecapacitor 20 can be coupled between the conductor exposed portions 7A 7B7C in a state of being inserted into the recess portions 15, so that thespace for the circuit elements within the housing 1 can be saved and sothe mounting density of the circuit elements can be enhanced.

Thus, the non-contact type rotational position sensor, which can besummed up the parts, miniaturized, simplified in its assemblingprocedure and made highly accurate, can be realized.

Further, since the upper and lower stators 4, 2A, 2B are held by thesensor cover 5 and the housing 1 before the assembling procedurethereof, when the cover is attached to the housing, the upper and lowerstators can be relatively positioned automatically to each other.Further, since the magnetic projections and the hall ICs are alsoconfigured to be disposed in the vertical direction together with thestators, the sensor can be further summed up the parts, miniaturized,simplified in its assembling procedure and made highly accurate.

FIG. 3 is a schematic diagram showing the throttle valve apparatusaccording to the second embodiment of the invention.

The second embodiment differs from the first embodiment in a point thatthe TCM as well as the circuit mold chips (sensor chips) 6 for thethrottle position sensor are incorporated within the gear cover 100. Thecircuit configuration of each of the circuit mold chip 6 and the TCM issame as FIG. 1. The conductors for coupling the circuit mold chip 6 withthe TCM may be wired at the gear cover 100 through the insert molding.

FIG. 4 is a schematic diagram showing the throttle valve apparatusaccording to the third embodiment of the invention. The third embodimentdiffers from the first embodiment in a point that the TCM and the ECU(the engine control unit) as well as the circuit mold chips (sensorchips) 6 for the throttle position sensor are incorporated within thegear cover 100. The circuit configuration of each of the circuit moldchip 6 and the TCM is same as FIG. 1.

The ECU receives a signal from an accelerator depression amount sensorthereby to calculate a target opening degree instruction signal. The ECUincludes an input/output interface, a ROM having control program, a RAMfor reading out the control program and storing sensor signals ofvarious kinds of engine states, and a CPU for performing calculationprocessing.

FIG. 5 is a schematic diagram showing the throttle valve apparatusaccording to the fourth embodiment of the invention. The fourthembodiment differs from the first embodiment in a point that the circuitmold chips (sensor chips) 6 for the throttle position sensor and the ECUare incorporated into the gear cover 100 and the control function of theTCM is contained in the CPU of the ECU. The A/D converter, the digitalzero span adjustment circuit and the temperature compensation circuitserving as the pre-stage circuits of the ECU are incorporated into thegear cover 100. Further, a motor driver circuit is incorporated into thegear cover 100. The CPU of the ECU calculates the motor drive currentand performs the feedback control.

According to the present invention, in the rotation angle detectingelement, the hall element signal processing apparatus, the throttlevalve control apparatus, wasteful or duplicated conversion processing ofthe hall element can be eliminated, so that the output of the hallelement can be applied to the processing circuit at the succeeding stageas early as possible thereby not to cause control delay etc. of thedevice, for example.

1. A signal processing apparatus for a hall element comprising: a hallelement; a microcomputer for inputting an output of the hall elementhaving been converted from an analog signal into a digital signal andoutputting an electric signal relating to the output of the hallelement; and a signal transmission path from an output terminal of thehall element to an input interface of the microcomputer, wherein thesignal transmission path has only one analog-to-digital conversioncircuit.
 2. A signal processing apparatus for a hall element accordingto claim 3, wherein the output of the analog-to-digital conversioncircuit is transferred to the microcomputer through a communicationline.
 3. An output signal processing apparatus for a hall element whichincludes two hall elements disposed at different positions along arotation direction of a rotation shaft and each responsive to rotationof the rotation shaft, and which is arranged to output a signal relatingto a rotation position of the rotation shaft based on output signalsfrom the two hall elements, the output signal processing apparatus for ahall element comprising: a casing for holding the two hall elements; twoamplifiers for amplifying outputs of the two hall elements, the twoamplifiers being attached to the casing; a connector, formed at thecasing, for extracting outputs of the two amplifiers; a circuitapparatus, coupled to the connector, for receiving the output signal ofthe hall element, wherein an analog-to-digital conversion circuit forconverting the output signal of the hall element is provided at thecircuit apparatus.